Biochemist Hank Pym discovered a rare group of subatomic particles, from which he formulated a size-altering serum. Testing the solution on himself, he found it was far more powerful than he had hypothesized. Reduced unexpectedly to the size of an insect, Hank became trapped in an anthill and narrowly escaped its inhabitants. Hank then undertook an exhaustive study of ants, devising a cybernetic helmet that enabled him to communicate with insects. Forced to employ his size-changing serum and new intervention to prevent the theft of his research, Hank was inspired to embark on a career as the costumed adventurer Ant-Man. After Ant-Man helped found the Avengers, Hank developed a second serum that enabled him to grow to greater-than-normal heights and adopted the guise of Giant-Man, and later Goliath.